Releasable chain stopper



N. P. THOMSEN 2,623,255

Dec. 30, 1952 RELEASABLE CHAIN STOPPER 3 Sheets-Sheet l Filed Sept. 27, 1950 9../RNEY INVENTOR /Vknameg BY K5 Cf. Ww

ATTORNEY 3 Sheets-Sheet 2 N P THOMSEN RELEASABLE CHAIN STOPPER Dec. 30, 1952 Flled Sepl 27 1950 DCC. 30, 1952 N P THOMSEN 2,623,255

RELEASABLE CHAIN STOPPER Filed Sept. 27, 1950 3 Sheets-Sheet 5 I N VENTOR /Va'eZQs Z? Mme@ BY ATTORNEY Patented Dec. 30, 1952 UNITED STATES PATENT OFFICE 2,623,255 RELEAsABLn CHAIN sroifrnn Niels P. Thomsen, Toledo, Ohio Application september 27, 1950, serial No. 186,981)

(Granted under the act of March 3,` 18,83, as amended April 30, 1928; 376 0. Gr. 757) 1 Claim;

The invention described hereinA mayV be manufactured and used` by or!" for' the Government of the United States` for governmental purposes without payment' to me of.` any royalty thereon in accordancey with the provisions of the act of April 3U, 1928 (ch. 460,45 Stat. 467)".

This invention relates' to devi-cesL for the han dling of heavy chain; and more particularly to a chain stopper.

There are many activitiesirr marine operations wherein heavy chain', often under strain, must be handled in a varietyy of ways. For example, buoy tenders must handley heavy lbuoy chain loaded by its: owrr weight andi often by the weight of thebuoy sinkeror anchor. At` present, thisis done'with pelican-hooksablock and tackle, manila lines', Winches,y and* booms with which chain, often stilli dragging; inf the water so-as to constitute a dynamic.` and` live load, is:` hoisted over the deck of the ship. Chain-and rope under heavy load arev stretched,v across and' over the deck where men must work. When there is aV failure in a hook.. block, hoisting line, oryang line,.or whenthepower driving a winchlor boom fails, or when any one of; atrium-ber of other incidents whichv cannot. alwaysv be prevented y occurs, all the personnel Working in thearea are subjected to the dangers of a:whipping heavy chain and objects falling from the boom. These hazards have necessitatedthat heavy chain under load be handled,in-afslow,cautious manner inconsistent with rapid work.y ,4

It is, therefore;` ,ani object'` of this invention to provide a device Whic-hwill enable men to handle heavy chain more rapidly) and efliciently.

It is afurther objectof this-invention to provides, device, the use of; which will removethe hazards from chain handling.V

These obiectsare accomplished by this invention which comprises aislotted-.member or plate, the top edge of which forms a series of` guide surfaces which direct moving chain into the slot in the slotted'member in which chain will catch, along with means for hinging the slotted member to the deck and'for'holding itin'an upright position for catching` the chain, and' in a downwardly slanting position for releasing thechain.

The inventionwill bemade clear by. reference to the followingy description and accompanying drawing, wherein:

Figure Iis a pictorialviewshowing the back sidefof an embodiment Aof ther device adapted for mounting onthe deck of a shipand adjacent to a bulkhead..

Figure IIis a. View of therfsame embodiment taken .fromabove and directlys behind the device, showing. it in the` full, open or-` chain releasing position;

Figure IIIl is a pictorial -detailfof the hinge lock;

Figure IV is a vertical longitudinal i section 2 taken approximately on line IV-IV of Figure I, showing the device' in closed and partially open positions;

Figure V isa vertical section taken approximately on line IV--IV of Figure l, showing the device in fully open or chain releasing position.

Figure VI is a front elevation of an embodi ment of the device adapted for use on an open dock', or for use on a ship deck away from any bulkhead or stanchion;

Figure VII is 9, side elevation of the device in the closed position, with chain being drawn through the V so that the chain will automatically become secured whenit is released.

Figure VII is a detail of the spring in the stop chain.

Figure IX is section- IX-IX of Figure Vll, further illustrating the structure of the spring in the stop chain. l

Figure X is a back elevation of the hinge lock.

In the preferred embodiment illustrated, chain is actually stopped in a vertical slot i, open at the top, whichis cut ina` stopmember or slotted plate 2l (see Figure D. The" upper edges or the slotted plate 2` forni a seriesoi` guide surfaces 3 and lisuch that if a' chain hanging over the side of the deck is moved toward the slot l it will. be` directed by the guide surfaces into the slot. The preferred embodiment has' guide surfaces i extending upward from each side of the slot i in the form of a` V. A guide surfaceiextends from the top of" one'sid'e of the V` 4 downward toward the deck, preferably at an angle with the decir` ci the order of 35 or less so that chain will slide easily upward and over it into the V4 When the deviceis installed adjacent to abulkhead or rail, there need be onlyl one guidesurface and the opposite side 5 ofV the slotted 'plate L" is vertical to fit adjacent to such bulkhead E5; as shown in Figure i. But when the device islinstalled on an open edge ci a` deck or dock; then a similar guide surface 3" is on the other `side as shown in FigureVi. rl-he thickness of the slotted plate is somewhat less thanthe distance between odd chain links.

Suitable means for hingedly fastening the slotted plate to a base such as adeck or dockare provided as shown in Figures I', TI, IV, V, and Vl. Paraleltothebottomedge of' the plate 2, there is a hingeshat id journalled in bearings in lugs il which protrude' from the slotted plate The*hingeshaftJ lil is rotatably mountedparallel to the deck oi the' shipby stationarylugs i2, and triangle blocks 1,3` which arerigidly secured the deck. The triangle blocks` serve a dual function asa mounting iorthe' end'of the hinge sha-it and as the lower end of"`theguidesurfac`e 3;

Suitable means are Ialso provided (see Figure VII)l for holding the slotted plate 2 inseated position that is roughly vertical and fcr releasingit toV permitrotationto an' open position at which the slotted plate slants downward from its base edge (see Figures IV and V). Protruding from the back of the plate 2 is an arm I 5 rigidly secured at one end to the slotted plate 2 by braces IB. At the free end of the arm I5, a hinge latch I'I is hinged to the deck so that it may be swung up over the end of the arm I5 to latch it in its seated position as in Figures I and VII, or off of the arm so as to free it as in Figures II, IV, and V. The seated position will normally be with plate 2 near vertical, but any predetermined position relative to the chain or the axis thereof, at which the chain will catch securely, will be satisfactory. Through the hinge latch Il and through the free end of the arm I5, holes I8 and I9 are drilled so that a lock pin 2i) may be inserted to prevent accidental unlatching of the arm. The holes may be through the hinged latch I'I and the arm rests 2|, if desired.

Suitable means for limiting the angular movement of the slotted plate 2 while the chain is being released are also provided. For example, a stop chain may be secured to the deck and to the bottom of the arm I5 of such length as to stop the rotation of the slotted plate 2 about its base at an open position at which chain will slide out of the slot I (see Figures II and V). Preferably there is a tension spring 26 in the stop chain 25 which can absorb the shock of stopping the rotation of the plate 2 and arm I5, and, more important, will operate to automatically return the arm I5 .to its seated position after the chain has been released.

Operation When a long chain is being hoisted aboard `a ship, it is usually hoisted in steps, no step any larger than the distance from the hoisting boom to the deck of the ship. A link of the chain is hooked and hoisted up. Then the chain is secured at the deck while a new link further down is hooked. In the operation of this invention, the chain is hoisted upward over the side of the ship and as it is hoisted is moved laterally toward the slot in the chain stopper. The chain rides over the guide surface 3 until it gets into the V It. When the pulling stops, the chain links fall into land are caught by the slot I. The stop member is held in its seated position by the hinge latch I7 in cooperation with the arm I5. When a new link is hooked and is hoisted up as shown in Figure VII, the chain comes out of the slot and moves upward, sliding through the V 4. If the hoisting power fails, the chain stopper catches the chain promptly so that the chain is not lost over the side of the ship and so that there is no danger to personnel. It is to be observed that the chain is secured at the very edge of the deckthere is no chain or line stretched across the deck which is under load as in all previous systems of handling heavy chain. When it is desired to drop chain over the side, the latch pin 20 may be removed, and the hinged latch may be opened as illustrated in Figure IV by a man standing a safe distance from any moving chain. The chain stopper will rotate to the open position shown in Figures II and V, releasing the chain over the side, and then by the action of the spring 26 in the stop chain 25 will reseat itself in the upright position.

Any one size of the chain stopper can handle a variety of sizes of chain, as from 5A," to 2" in diameter, and with a U bracket tted into the slot I can handle even smaller sizes. The hinging of the slotted member at its very end makes it impossible for the chain to yget caught thereunder. Practical tests of the Vinvention abo-ard buoy tenders have revealed many other advantages inherent in the device. The buoy deck can be completely cleared of all personnel until the chain is automatically and safely secured at the outside edge of the buoy port. The invention eliminates entirely the use of Manila lines, snatch blocks, and pelican hooks from the buoy deck. In the event of casualty to hoisting gear, the device prevents the loss of chain over the side and its eliminates the dangers of a chain Whipping about the deck where men are working. It particul-arly simplifies the dropping of sinkers, taking the place of teeterboards, slip. lines, and pelican ho-oks. It removes for the greater part, the strain and tension on personnel directly handling or supervising buoy handling operations, by

eliminating the probability of sudden and serious injury through circumstances beyond their control-falling objects, failure of hooks, blocks, straps, hoisting lines, and vang lines. By eliminating certain operations, and by releasing personnel from fear of injury, the invention speeds up overall buoy handling from 100 to 200 per cent,

and permits buoy handling in unfavorable current and weather conditions without unduly endangering personnel. It substantially reduces the personnel requirements on the'average buoy deck,

and the device permits the standardization of the work methods employed in chain handling to an extent not previously possible. These advantages already experienced in buoy handling,

are inherent in the device and will be experienced in its application to other chain handling activities.

It is `clear that various modifications of the invention as described c-an bemade without departure from the spirit or the scope thereof.

` being parallel to the plane of the margins of said slot and guiding surfaces, an arm rigidly united with said stopper, latching means for releasably latching said arm for at will holding said stopper in chain suspending position and shock absorbing means for arresting the pivotal movement of said stopper when released.

NIELS P. THOMSEN.

REFERENCES CITED The following references are of record in the le of this patent:

UNITED STATES PATENTS Number Name Date 157,736 Coffin Dec. 15, 1874 160,363 Thompson Mar. 2, 1875 176,562 Marie Apr. 25, 1876 276,841 Lynch 1 Ma'y 1, 1883 678,798 Stretch July 16, 1901 1,181,000 Gregg Apr. 25, 1916 1,224,148 Crosby May 1,1917 1,474,680 Lyon Nov. 20, 1923 1,774,891 Kidwell Sept. 2, 1930 2,094,516 Amann Sept. 28, 1937 2,481,443 Pawlanskyl Sept. 6, 1949 

